magnetic lens changing system for all weather conditions . the sinner sin valley is a high performance goggle with magnetic lens change system. this allows you to change lenses in less than 5 seconds to adapt them to the weather conditions. the ingenious ventilation system and the anti-fog coating prevent fogging of the lens. the soft, 3-layer hypoallergenic foam on the inside provides an excellent fit and maximum comfort.pink mirrorthis lens is perfect for sunny and slightly cloudy days on the mountain.transmittance of visible light: 8-18 %